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40 result(s) for "Ben-Shachar, Shay"
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Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2-mRNA-vaccinated individuals
The BNT162b2 mRNA vaccine is highly effective against SARS-CoV-2. However, apprehension exists that variants of concern (VOCs) may evade vaccine protection, due to evidence of reduced neutralization of the VOCs B.1.1.7 and B.1.351 by vaccine sera in laboratory assays. We performed a matched cohort study to examine the distribution of VOCs in infections of BNT162b2 mRNA vaccinees from Clalit Health Services (Israel) using viral genomic sequencing, and hypothesized that if vaccine effectiveness against a VOC is reduced, its proportion among breakthrough cases would be higher than in unvaccinated controls. Analyzing 813 viral genome sequences from nasopharyngeal swabs, we showed that vaccinees who tested positive at least 7 days after the second dose were disproportionally infected with B.1.351, compared with controls. Those who tested positive between 2 weeks after the first dose and 6 days after the second dose were disproportionally infected by B.1.1.7. These findings suggest reduced vaccine effectiveness against both VOCs within particular time windows. Our results emphasize the importance of rigorously tracking viral variants, and of increasing vaccination to prevent the spread of VOCs. At early time points after vaccination with a single dose or two doses of the BNT162b2 mRNA COVID-19 vaccine, breakthrough SARS-CoV-2 infections can be disproportionately caused by the B.1.1.7 or B.1.351 variants of concern, underlining the need to ensure rapid and complete vaccination.
MHC Haplotyping of SARS-CoV-2 Patients: HLA Subtypes Are Not Associated with the Presence and Severity of COVID-19 in the Israeli Population
HLA haplotypes were found to be associated with increased risk for viral infections or disease severity in various diseases, including SARS. Several genetic variants are associated with COVID-19 severity. Studies have proposed associations, based on a very small sample and a large number of tested HLA alleles, but no clear association between HLA and COVID-19 incidence or severity has been reported. We conducted a large-scale HLA analysis of Israeli individuals who tested positive for SARS-CoV-2 infection by PCR. Overall, 72,912 individuals with known HLA haplotypes were included in the study, of whom 6413 (8.8%) were found to have SARS-CoV-2 by PCR. A total of 20,937 subjects were of Ashkenazi origin (at least 2/4 grandparents). One hundred eighty-one patients (2.8% of the infected) were hospitalized due to the disease. None of the 66 most common HLA loci (within the five HLA subgroups: A, B, C, DQB1, DRB1) was found to be associated with SARS-CoV-2 infection or hospitalization in the general Israeli population. Similarly, no association was detected in the Ashkenazi Jewish subset. Moreover, no association was found between heterozygosity in any of the HLA loci and either infection or hospitalization. We conclude that HLA haplotypes are not a major risk/protecting factor among the Israeli population for SARS-CoV-2 infection or severity. Our results suggest that if any HLA association exists with the disease it is very weak, and of limited effect on the pandemic.
The effect of parental age on the presence of de novo mutations – Lessons from neurofibromatosis type I
Background Neurofibromatosis type 1 (NF1) is the most common autosomal dominant neurocutaneous disease with a prevalence of 1:2500. Approximately, 50% of the cases are sporadic. Advanced paternal age is associated with germline mutations and autosomal diseases. We aimed to use NF1 as a paradigm to study the effect of parental age on sporadic mutation rates for both advanced and younger parental ages. Methods The medical charts of 118 NF1 pediatric patients followed in a specialized Israeli NF1 clinic were evaluated. Thirty‐one cases were diagnosed by genetic tests and 87 by NIH clinical criteria. Sixty‐four cases (54%) had a negative family history of NF1 (sporadic cases). Data on parental ages at the time of the children's birth were compared to the national population database. Results Parental age of children with sporadic NF1 was higher than the general population (32.7 years vs. 30.1 years, respectively, for the mothers and 36.5 years vs. 32.6 years, respectively, for the fathers; P < 0.0001 for both groups). In contrast, the age of the mothers and the fathers in the familial cases (30.3 and 33.9 years, respectively) did not differ from the general population. Significantly, fewer fathers of the sporadic group had been 25–29 years old at their child's birth compared with fathers in the general population (7.8% vs. 21%, respectively, P = 0.009), and significantly more fathers were ≥40 years old (29.7% vs. 13.6%, respectively, P = 0.0002). Differences in maternal age between these two groups were less prominent. Conclusion Parents of sporadic NF1 cases are older. The risk for sporadic NF1 was lower when the fathers were younger at the time of the affected child's birth, and gradually increased with paternal age. The study aims to use Neurofibromatosis type 1, a common autosomal dominant neurocutaneous disease, as a paradigm to study the effect of paternal age on autosomal dominant diseases. The results demonstrated that advanced paternal age is a risk factor and that young paternal age is protective. This effect may also hold true for other autosomal dominant disorders with de novo occurrence.
Variants in SART3 cause a spliceosomopathy characterised by failure of testis development and neuronal defects
Squamous cell carcinoma antigen recognized by T cells 3 ( SART3 ) is an RNA-binding protein with numerous biological functions including recycling small nuclear RNAs to the spliceosome. Here, we identify recessive variants in SART3 in nine individuals presenting with intellectual disability, global developmental delay and a subset of brain anomalies, together with gonadal dysgenesis in 46,XY individuals. Knockdown of the Drosophila orthologue of SART3 reveals a conserved role in testicular and neuronal development. Human induced pluripotent stem cells carrying patient variants in SART3 show disruption to multiple signalling pathways, upregulation of spliceosome components and demonstrate aberrant gonadal and neuronal differentiation in vitro. Collectively, these findings suggest that bi-allelic SART3 variants underlie a spliceosomopathy which we tentatively propose be termed INDYGON syndrome ( I ntellectual disability, N eurodevelopmental defects and D evelopmental delay with 46,X Y GON adal dysgenesis). Our findings will enable additional diagnoses and improved outcomes for individuals born with this condition. The SART3 gene encodes an RNA-binding protein critical for spliceosome function. Here, the authors find that bi-allelic variants in SART3 underlie a congenital condition characterised by neuro-developmental defects and 46,XY gonadal dysgenesis.
The time-consuming demands of the practice of medical genetics in the era of advanced genomic testing
Clinical genetics services are time- and labor-intensive. With increasing pressure for cost-effective medical care, the means of providing medical genetics services need to be evaluated in the current era of new genomic technologies. An anonymous online survey regarding activities linked to medical genetics practice was administered to an international cohort of professionals. Among 151 responses, the reported average time required for pediatric, oncogenetic, pregnancy with a malformed fetus, and preamniocentesis counseling sessions was 48, 37, 40, and 18 min, respectively. The time required to prepare a summary letter followed a similar pattern. Professionals with less experience needed more time for specific activities. The time required for the total workup of a pediatric patient ranged from 1 h and 48 min to 4 h, most of which was associated with indirect activities. Professionals performing one type of consultation (74% pediatric geneticists) perform fewer consultations per week. Respondents’ narrative comments reflected the complexity of the work and challenges faced. Clinical genetics is a time-consuming profession with increased demands related to advanced genetic and genomic testing. Further consideration is required to determine how to adapt these changes to the demands of cost-effectiveness without compromising the quality of patient care.
A Novel Pathogenic Variant Identified in HIKESHI-Related Hypomyelinating Leukodystrophy Disrupts Heat Shock Response in iPSCs
HIKESHI-related hypomyelinating leukodystrophy (HHL) is a life-threatening disorder caused by homozygous pathogenic variants in HIKESHI. Symptoms include infantile onset progressive spastic dystonic quadriplegia, nystagmus, failure to thrive, diffused hypomyelination, and severe morbidity or death following febrile illness. V54L variants in HIKESHI are particularly prevalent within the Ashkenazi Jewish population. Here, we identified a novel P78S disease-causing variant in HIKESHI in a patient of Christian Arab origin, presenting with clinical and radiologic features characteristic of HHL. In silico analysis suggests that the mutated residue may affect the HIKESHI protein’s dimerization domain. We generated a comprehensive set of induced pluripotent stem cells (iPSCs) from the index case and two additional HHL patients. To investigate mechanisms potentially linked to febrile illness in HHL, we used these cells to study the heat shock (HS) response. HHL-iPSCs showed dramatically decreased levels of HIKESHI compared with healthy controls following HS. In addition, they exhibited increased HSP70 mRNA levels in response to HS, suggesting an increased sensitivity. HHL-iPSCs had impaired HSP70 translocation to the nucleus. Our results provide a human-relevant model for HHL.
The rare 13q33–q34 microdeletions: eight new patients and review of the literature
The objective of this study is to shed light on the phenotype and inheritance pattern of rare 13q33–q34 microdeletions. Appropriate cases were retrieved using local databases of two largest Israeli centers performing CMA analysis. In addition, literature search in PubMed, DECIPHER and ClinVar databases was performed. Local database search yielded eight new patients with 13q33.1–q34 microdeletions (three of which had additional copy number variants). Combined with 15 cases detected by literature search, an additional 23 cases were reported in DECIPHER database, and 17 cases from ClinVar, so overall 60 patients with isolated 13q33.1–q34 microdeletions were described. Developmental delay and/or intellectual disability were noted in the vast majority of affected individuals (81.7% = 49/60). Of the 23 deletions involving the 13q34 cytoband only, in 3 cases, developmental delay and/or intellectual disability was not reported. Interestingly, in two of these cases (66.7%), the deletions did not involve the terminal CHAMP1 gene, as opposed to 3/20 (15%) of patients with 13q34 deletions and neurocognitive disability. Facial dysmorphism and microcephaly were reported in about half of the overall cases, convulsions were noted in one-fifth of the patients, while heart anomalies, short stature and hypotonia each involved about 10–30% of the cases. None of the 13q33–q34 deletions were inherited from a reported healthy parent. 13q33–q34 microdeletions are rare chromosomal aberrations, associated with high risk for neurodevelopmental disability. The rarity of this chromosomal aberration necessitates continuous reporting and collection of available evidence, to improve the ability to provide accurate genetic counseling, especially in the context of prenatal setting.
The effect of polyhydramnios degree on chromosomal microarray results: a retrospective cohort analysis of 742 singleton pregnancies
Purpose To analyze the risk for clinically significant microarray aberrations in pregnancies with polyhydramnios. Methods Data from all chromosomal microarray analyses (CMA) performed due to polyhydramnios between January 2013 and December 2019 were retrospectively obtained from the Ministry of Health Database. The rate of clinically significant (pathogenic and likely pathogenic) CMA findings in isolated and non-isolated polyhydramnios cohorts was compared to a local control group of 5541 fetuses with normal ultrasound, in which 78 (1.4%) abnormal results were demonstrated. Subgroup analyses were performed by the degree of polyhydramnios, week of diagnosis, maternal age, and the presence of additional sonographic anomalies. Results In the isolated polyhydramnios cohort, 19/623 (3.1%) clinically significant CMA aberrations were noted, a significantly higher rate compared to the control population. However, the risk for abnormal CMA results in the 158 cases with mild polyhydramnios (AFI 25–29.9, or maximal vertical pocket 8–11.9 cm) did not significantly differ from pregnancies with normal ultrasound. Of 119 cases of non-isolated polyhydramnios (most frequently associated with cardiovascular (26.1%) and brain (15.1%) anomalies), 8 (6.7%) abnormal CMA findings were noted, mainly karyotype-detectable. Conclusion Mild polyhydramnios was not associated with an increased rate of clinically significant microarray results, compared to pregnancies with normal ultrasound. An extensive anatomical sonographic survey should be performed in pregnancies with polyhydramnios, with consideration of fetal echocardiography.